Study of the Coordination Modes of Hybrid NNCp Cyclopentadienyl/Scorpionate Ligands in Ir Compounds

A new coordination mode for the hybrid scorpionate/cyclopentadienyl ligand bpzcp, [bpzcp = 2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethylcyclopentadienyl] is observed in iridium complexes. The reaction of the lithium precursor, [Li(bpzcp)(THF)], with a range of [IrCl(diene)]2 compounds leads to an unprecedented binding mode of the hybrid scorpionate/cyclopentadienyl ligand as ?5-Cp-coordinated and the formation of Ir(I) derivatives [Ir(?5-Cp-bpzcp)(?4-cod)] (1), [Ir(?5-Cp-bpzcp){?4-CH2?C(Me)C(Me)?CH2}] (2), [Ir(?5-Cp-bpzcp)(?2-coe)2] (3), and [Ir(?5-Cp-bpzcp)(?2-CH2?CH2)2] (4). The Ir(I) complex 4 reacts with CO or bromine to afford the compound [Ir(?5-Cp-bpzcp)(CO)2] (5) and the 18e? Ir(III) complex [Ir(?-N-?5-Cp-bpzcpBr2)Br2] (6), respectively. Reaction of the iridium compounds (2?4) with CuI or [PdCl2(CH3CN)2] yields the heterobimetallic iridium?copper or iridium?palladium complexes [Ir(?5-Cp-bpzcp){?4-CH2?C(Me)C(Me)?CH2}(?-bpzcp){CuI(?2-NN-bpzcp)}] (7), [Ir(?5-Cp-bpzcp)(?2-coe)2}(?-bpzcp){CuI(?2-NN-bpzcp)}] (8), [Ir(?5-Cp-bpzcp)(?2-CH2?CH2)2}(?-bpzcp){CuI(?2-NN-bpzcp)}] (9), [Ir(?5-Cp-bpzcp)(coe)2}(?-bpzcp){PdCl2(?2-NN-bpzcp)}] (10), and [Ir(?5-Cp-bpzcp)(?2-CH2?CH2)2(?-bpzcp){PdCl2(?2-NN-bpzcp)}] (11). All products were characterized by spectroscopic methods and the X-ray crystal structures of 1, 2, 3, 4, and 6 were also established.